(1) Field of the Invention
The present invention generally relates to a communication system capable of changing a calling mode and a terminal used in the communication system, and more particularly to use of a terminal in a communication system constructed in a network, such as an ISDN, to which terminals can be connected in a plurality of modes, and in which a mode can be changed between terminals.
(2) Description of the Related Art
In a communication system constructed in an ISDN, each terminal can communicate with another terminal in any of a plurality of modes, such as an audio communication mode, a 64 kbps data communication mode and the like. In a communication system constructed in a network to which terminals can be in a plurality of modes, if a specific mode of a calling terminal is not set in a terminal that is being called, the calling terminal recognizes that the called terminal is in a busy state.
A user of the calling terminal which recognizes that the called terminal is in the busy state must repeatedly recall by changing the mode until the changed mode is the same as the mode set in the called terminal. As a result, it is often difficult and time consuming to connect the terminal to the network.